Selected Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2017

Quarterly Financial Information Disclosure [Abstract]

Selected Quarterly Financial Data

	December 31		September 30		June 30		March 31
	(in thousands, except for per share data)
2017
Total revenues	$	3,285,755	$	2,984,859	$	2,785,464	$	2,636,635
Gross profit	1,178,401		991,879		883,156		979,611
Net income	185,517		129,590		65,600		178,222
Earnings per share:
Basic	$	0.43	$	0.30	$	0.15	$	0.41
Diluted	0.41		0.29		0.15		0.40
2016
Total revenues	$	2,477,541	$	2,290,188	$	2,105,204	$	1,957,736
Gross profit	823,122		757,344		632,106		588,196
Net income	66,748		51,517		40,755		27,658
Earnings per share:
Basic	$	0.16	$	0.12	$	0.10	$	0.06
Diluted	0.15		0.12		0.09		0.06